Delta wing car concept

Please discuss here all your remarks and pose your questions about all racing series, except Formula One. Both technical and other questions about GP2, Touring cars, IRL, LMS, ...

Post Thu Jun 09, 2011 7:10 pm

You probably end up needing to control rear wheel braking and drive distribution so finely you end up with a giant segway with a small tiller at the front. I think it could still work, but like I said, you end up steering with the rear wheels more than ever before.

Maybe they are thinking about it in a way similar to how canards prevent stalling in certain aircraft. Canards stall before wings, plane returns to normal pitch = front wheel designed to lose grip before rear, rear wheels pull front end back toward centerline. Basically, the back end can't step out, instead you understeer off into oblivion, unless, you have some nice active rear brake distribution to keep the car rotating.
Formula None
 
Joined: 17 Nov 2010

Post Thu Jun 09, 2011 9:03 pm

gridwalker wrote:Personally, I hope they dominate.

Everyone had their doubts about the funny little rear engined cars that John Cooper entered into F1 alongside the traditional front engined cars, but look where that ended up ... people are always reluctant to adapt to a new form factor or engineering methodology (Carbon Fibre chassis were originally written off as fragile and dangerous) but sometimes these oddball technologies become an epoch-changing development.

I wish them all the best at Le Mans, but I doubt they'll live up to my hopes.


I'm with you, gridwalker. Gordon Kirby had an interesting piece on this car some time ago:
http://www.gordonkirby.com/categories/c ... no268.html
Seems like it has been pretty thoroughly thought out . . .
Enzo Ferrari was a great man. But he was not a good man. -- Phil Hill
donskar
 
Joined: 3 Feb 2007
Location: Cardboard box, end of Boulevard of Broken Dreams

Post Thu Jun 09, 2011 9:27 pm

Another thing to consider with the DW design:

With the outrageous difference in front to rear track width, the lateral load transfer distribution is going to be immensely biased to the rear. Admittedly, who knows what kind of load distribution this thing will need to be balanced with whatever tires it has.. though again typically as you take out static nose weight you are heading to oversteer.

Does make me wonder how tune-able the thing is.

Personally, I'm not a fan of the concept.
Grip is a four letter word.

2 is the new #1.
Jersey Tom
 
Joined: 29 May 2006
Location: Huntersville, NC

Post Thu Jun 09, 2011 9:49 pm

"Why the delta wing will work" --
http://www.gordonkirby.com/categories/c ... no238.html

Some interesting technical opinions here. Firestone thinks that the simulations predict success. Barnard has some doubts, which Bowlby and Firestone reply to.
Enzo Ferrari was a great man. But he was not a good man. -- Phil Hill
donskar
 
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Location: Cardboard box, end of Boulevard of Broken Dreams

Post Thu Jun 09, 2011 10:10 pm

On the braking stability; perhaps the two big front tyres operating so far from the CG you will give you a lot of yaw damping which could help stability under brakes? Albeit, a pretty backwards way of doing it, but regardless, if they really manage to develop a formula which can lap at the same speeds as current lmp car with half the power then thats a pretty amazing feat.

OK, the vehicle dynamics maybe compromised due to the layout but you only need to look to formula 1 to see how much the front and rear suspensions have been "compromised" for aerodynamic benefits.

Tim
Not an engineer at Caterham F1
Tim.Wright
 
Joined: 13 Feb 2009

Post Thu Jun 09, 2011 10:22 pm

Lighten up JT, its just a race car. :wink: I guess they're your bread and butter though and no longer a source of entertainment. *kidding* I think it will be fun to see it develop & race, and fun to watch it fail or succeed.

Tim.Wright wrote:...if they really manage to develop a formula which can lap at the same speeds as current lmp car with half the power then thats a pretty amazing feat.


I think this could already be happening with standard wheel arrangements if they'd eliminate or lower the min weight regs, and loosen up some of the aerodynamic rules. The Delta wing layout, to me, seems to be more of an experiment in weight distribution & low aero drag.
Formula None
 
Joined: 17 Nov 2010

Post Thu Jun 09, 2011 10:58 pm

From the top of my head (bad idea, but I'm in a hurry).

RabMcH wrote:If you take a look at the past few Indy car races, many drivers are involved in collisions involving a cars front wing being picked up by the rear wheel, of the car in front, cause full course yellows and thus making the race more boring, these covers should reduce that chance and allow for a more competitive race. :)


Sure. I completely agree.

I think that's their primary function. Ugly or not, they are beautiful from the point of view of safety.

I don't know if those fenders can also double as mini-diffusers, the same way that the curved bottom part of the rear crash structure is used by some F1 teams. They seem, to my untrained eye (only trained here, so you can imagine the results...) that they are in the same general plane of the "main" diffuser.

I also love the Deltawing model. It seems to me that the concept is solid.

Can I say that it is insensitive to wing height? Or am I mistaken? The more I think about it, the more I like it, to be sincere. If you control stability through differential action of rear wheels and most of the weight is there, then the yaw inertia is very low.

Is it like those toys that have a low CG and can balance in the most strange positions, but horizontally instead of vertically?

If you generate downforce on the same "sweet spot", with a stable rear wing instead of a frontal wing that tumbles around at every curve, well, it seems a winner.

That's the reason (I think) that makes the car look like a "ground fighter". The constraints about wing position in relationship to CG could be very similar. Is that true?

Coupled with an active rear differential (if that's what I think it is) it means you have a Segway-like vehicle, but not vertical: longitudinal.

Final question: don't you reduce the scrub angle necessary for yaw if you apply differential forces to the rear wheels? Actually, you could have an (what I think is) essentially the zero scrub angle of vehicles like tanks, that work entirely by differential braking.

On top of that, you use the braking force (or the accelerating force) to steer, instead of using part to steer and part to brake. Am I mistaken?

About aesthetics, besides the form vs function argument, I sincerely believe that the point of a racing car can be also its coolness.

I think both vehicles are cool, because they go way beyond (forgive me, gods of racing!) the "usual" constrained-by-the-rules-to-the-inch survivalist and minimalist design you can see in... erm, elsewhere.

I, as a proud third-world inhabitant, dare to think that the cooler part of these vehicles is their price.

I believe that's what distinguishes good from bad engineering, in the end (and since the beginning).
Ciro
Ciro Pabón
 
Joined: 10 May 2005

Post Thu Jun 09, 2011 11:15 pm

Jersey Tom wrote:The thing about majority of braking force coming from rear wheels being inherently stable is a load of BS.. as are many things in the DW design IMO.


I'm with you... if the rear weight + rear downforce + rear brake bias were beneficial why don't people make "rectangular" cars with the same bias'????!!!

What would be really annoying is if the AcO bias the rules to give this thing a helping hand... its not like they haven't done that in the past.... [cough] diesels [cough]....
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machin
 
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Post Thu Jun 09, 2011 11:16 pm

machin wrote:
Jersey Tom wrote:The thing about majority of braking force coming from rear wheels being inherently stable is a load of BS.. as are many things in the DW design IMO.


I'm with you... if the rear weight + rear downforce + rear brake bias were beneficial why don't people make "rectangular" cars with the same bias'????!!!

What would be really annoying is if the AcO bias the rules to give this thing a helping hand... its not like they haven't done that in the past.... [cough] diesels [cough]....


Porsche? Corvair? Not quite as drastic, but close.
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Post Fri Jun 10, 2011 12:43 am

You can do some interesting things with active differentials, Ciro - but there is a limit. Not quite what you are describing, which IMO is better left to 4-wheel steer.

Bear in mind for example that during combined cornering/braking or cornering/driving events, with load transfer and a lightly loaded inside tire there isn't too much you can do with it. Try to bias too much braking or driving torque to the lightly loaded inside tire and you will just lock it or spin it.

Obviously there is a benefit to being able to bias driving force to the outside tire on corner exit as it will have the most grip available. However, this is what limited slip and variable lock differentials essentially already do, and why on a F1 car for example the driver has the ability to control that amount of locking through the diff independently on entry (coast), middle (neutral), and exit (power).

In any event... efficient racing? No series truly cares (my opinion, not that of my employer or anyone associated!!). If we were truly interested in energy efficiency, why not always race at a place like Daytona or Talladega where you don't have to lift off the throttle? Race at huge open tracks where the reward is to he who has the slimmest drag coefficient. Or... reduce energy usage in F1? Okay, put 450 hp engines in. Make it FSAE with 80 hp engines.

There has never been, nor will ever be, relevance of racing "technology" and R&D to consumers. For that matter, consumer R&D budgets make F1 look like chump change.
Grip is a four letter word.

2 is the new #1.
Jersey Tom
 
Joined: 29 May 2006
Location: Huntersville, NC

Post Fri Jun 10, 2011 2:38 am

Thanks and sure, Tom. You know, I always exaggerate a bit. The Segway and a tank were examples. Extreme ones.

Anyway, the idea of a car with a huge floor for downforce, and coincidence of downforce and rear weight doesn't make you "inherently stable" because, AFAIK, everything is unstable in this world God has given us... but at least gives you enough stability to try the idea.

I work with soil, so the luxury some have here (at least the materials resemble predictability) about assuming that you can deduce how a thing is going to work, I don't have. I get the point.

Anway, I'd say that the design, once adopted this "rear pressure" principle, is pretty straighforward, like that of a jet. Without it, this thing would be Robin Part II

(thanks, superthanks for this video. Ex-ce-llent. I laughed for some time)

I don't know if it will work, but for the money involved (spare change of the spare change left in racing from the spare change left in production) the designers will have a heck of a time and they will be remembered for many, many years, no matter if it's a dud. Actually, you're remembered specially when your work is an spectacular dud. The larger the mistake, the larger the lesson.

I still remember the first car I saw with a wing. I said: "Nahhh, they must be joking. What can you do with a wing that you cannot do with the body?". I think this car is, for me, the answer to an old question.

Can I quote Mark Twain?

With your permission:

"Fewer things are harder to put up with than the annoyance of a good example."
Ciro
Ciro Pabón
 
Joined: 10 May 2005

Post Fri Jun 10, 2011 7:13 am

Formula None wrote:Porsche? Corvair? Not quite as drastic, but close.


The 911 GT3 road car reportedly has a weight bias of 38:62 (not that different from a typical mid-engined car)... Straight line acceleration and braking I can see the point -more weight over the rear wheels during acceleration and during braking forward weight transfer should get you nearer the 50:50 ideal... but cornering?

If this was a totally fair test they'd build a "rectangular" car with the same weight limit and the same power, and see which is better...


http://www.motortrend.com/roadtests/coupes/112_0705_2007_porsche_911_gt3/specs.html...%20so%20a%20good
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machin
 
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Post Fri Jun 10, 2011 11:19 am

what bothers me more with this car is safety. If you get t-boned in this thing you are way more likely to be screwed then with the other LMP's and even open seaters. I really wont want to be T-boned either by another Delta wing, making things even worse. I cannot understand how that thing can ever be safe, the front wheels will penetrate your tub or someone elses tub due to the position. The LMP's have what, at least 30cm on each of the tub sides of area that releases energy. Even with F1 cars, with still pretty exposed tub area you are way safer, in a T-bone accident alot of energy will first be released with the front wing, which will hit the car first.

I'm sorry For DWG, but i'd rather get hit by buemi's F1 car then get a crash with one of these things.
"Bite my shiny metal ass" - Bender
wesley123
 
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Post Fri Jun 10, 2011 1:57 pm

Actually, as the nose is light and long, I think it would fulfill the crash adsorbing function in a lateral impact.
Ciro
Ciro Pabón
 
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Post Fri Jun 10, 2011 2:32 pm

Jersey Tom wrote:Obviously there is a benefit to being able to bias driving force to the outside tire on corner exit as it will have the most grip available. However, this is what limited slip and variable lock differentials essentially already do...


It would be nice if an LSD put more torque to the outside wheel, but my understanding is the torque is highest on the slower moving wheel (which is the inside wheel if you are not sliping).

Tim
Not an engineer at Caterham F1
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